A turbomachine, such as a gas turbine engine, typically includes a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and, optionally, a fan section if the turbomachine is used as a propulsor.
The turbine section, as well as the compressor section, typically includes airfoils. Some airfoils rotate as blades and other airfoils are static vanes. Depending on the operating conditions, the airfoils are fabricated of a metal alloy, such as a nickel-based alloy. The airfoils can be cast in a desired design geometry from the selected metal alloy. Depending on the operating conditions, the airfoils may include a coating on the outside to protect the airfoil from thermal, environmental or other conditions.